Assessment of prestressed concrete bridge girders with low shear reinforcement by means of a non-linear filament frame model

The safety of existing bridges and the efficiency of strengthening measures can be accurately studied through non-linear numerical models, assisting decisions of dismantle, repair or change of use and avoiding unnecessary or inappropriate interventions. In this ambit, filament beam models due to their inherent simplicity and low computational demand are adequate for the engineering practice. Accordingly, in this paper, the structural assessment of a prestressed concrete bridge presenting low shear reinforcement, the Wassnerwald Viaduct in Switzerland, is presented. The bridge was dismantled due to, among other reasons, not complying with the safety standards related to shear. The girders of the bridge, which were submitted to full-scale in situ load tests, were numerically simulated by means of a non-linear filament beam model considering axial force (N)–shear (V)–bending (M) interaction. Hypothetical strengthening solutions for this bridge were also numerically studied: a shear strengthening through vertical prestressing and a bending strengthening through external longitudinal prestressing.